E. Coli Mecanismo Fisiopatologico

ERole of Motility in the Colonization of Uropathogenic Escherichia coli in the Urinary Tract
M. Chelsea Lane, Virginia Lockatell, Greta Monterosso, Daniel Lamphier, Julia Weinert, J. Richard Hebel, David E. Johnson and Harry L. T. Mobley Infect. Immun. 2005, 73(11):7644. DOI: 10.1128/IAI.73.11.7644-7656.2005.

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INFECTION AND IMMUNITY, Nov. 2005, p. 7644–7656 0019-9567/05/$08.00 0 doi:10.1128/IAI.73.11.7644–7656.2005 Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Vol. 73, No. 11

Role of Motility in the Colonization of Uropathogenic Escherichia coli in theUrinary Tract
M. Chelsea Lane,1 Virginia Lockatell,2 Greta Monterosso,3 Daniel Lamphier,2 Julia Weinert,3 J. Richard Hebel,4 David E. Johnson,2,5 and Harry L. T. Mobley3*
Department of Microbiology and Immunology,1 Division of Infectious Diseases,2 and Department of Epidemiology,4 University of Maryland School of Medicine, and Research Service, Department of Veterans Affairs,5 Baltimore, Maryland21201, and Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 481093
Received 16 May 2005/Returned for modification 30 June 2005/Accepted 26 July 2005

Uropathogenic Escherichia coli (UPEC) causes most uncomplicated urinary tract infections (UTIs) in humans. Flagellum-mediated motility and chemotaxis have been suggested to contribute to virulenceby enabling UPEC to escape host immune responses and disperse to new sites within the urinary tract. To evaluate their contribution to virulence, six separate flagellar mutations were constructed in UPEC strain CFT073. The mutants constructed were shown to have four different flagellar phenotypes: fliA and fliC mutants do not produce flagella; the flgM mutant has similar levels of extracellularflagellin as the wild type but exhibits less motility than the wild type; the motAB mutant is nonmotile; and the cheW and cheY mutants are motile but nonchemotactic. Virulence was assessed by transurethral independent challenges and cochallenges of CBA mice with the wild type and each mutant. CFU/ml of urine or CFU/g bladder or kidney was determined 3 days postinoculation for the independent challenges andat 6, 16, 48, 60, and 72 h postinoculation for the cochallenges. While these mutants colonized the urinary tract during independent challenge, each of the mutants was outcompeted by the wild-type strain to various degrees at specific time points during cochallenge. Altogether, these results suggest that flagella and flagellum-mediated motility/chemotaxis may not be absolutely required for virulencebut that these traits contribute to the fitness of UPEC and therefore significantly enhance the pathogenesis of UTIs caused by UPEC. Uropathogenic Escherichia coli (UPEC) infections account for more than 80% of uncomplicated urinary tract infections (UTIs) (40). UPEC infections occur in otherwise healthy individuals, with the majority of infections affecting women (40). In the year 2000, urinarytract infections resulted in an estimated 6.8 million physician visits, 1.3 million emergency room visits, and 245,000 hospitalizations of women, with an annual cost of more than $2.4 billion (23). Even for men, urinary tract infections resulted in 1.4 million physician visits, 424,000 emergency room visits, and 121,000 hospitalizations in the year 2000, with an economic burden of more than $1...